Reinforced Concrete Pipe Research Articles

Performance Assessment Framework for Reinforced Concrete Pipes in Rainwater Drainage System Using a Combined Weights-Fuzzy Theory

AbstractDue to the current deterioration of the environment, the performance degradation of reinforced concrete rainwater drainage pipes (RCRDPs) has become increasingly serious. Aiming at these pr...

Finite Element Analysis of Bearing Capacity of Reinforced Concrete Pipe Strengthened by TRC

A non-linear 3D finite element model was established to simulate the three edge-bearing test of TRC reinforced concrete pipe. The pipe load-displacement curve, cracking load, and ultimate load simulation values are in good agreement with the test values. Subsequently, a parametric study was conducted. The effects of reinforcement layer bonding mode, mesh size of concrete element, mesh distribution rate and concrete compressive strength on the performance of reinforced concrete pipeline strengthened by TRC were considered. It provides a basis for the design of TRC reinforced concrete pipes.

New rational test for reinforced-concrete pipe eliminating subjective crack-width criteria

This study proposes a new robust and rational test method for reinforced concrete pipe (RCP), which neither requires additional costly equipment, nor disrupts current industry practice. The current century old Three-Edge Bearing Test (TEBT), which is the most widely used worldwide, is operator sensitive and does not work well for emerging lined pipes. It relies on the skill and experience of the operator for capturing the occurrence of a 0.3 mm wide crack using a leaf-gauge, which induces subjectivity and error. TEBT was modified by eliminating visual crack width monitoring and adopting rational instrumentation. A wide range of full-scale RCP specimens with various diameters and single, double and triple reinforcing steel cage configurations were instrumented and subjected to the modified TEBT to obtain load vs. deflection curves. Traditional 0.3-mm visual crack readings were also taken for comparison. It was concluded that the new test method could determine the D-load while eliminating the uncertainty associated with visual crack detection. The new modified test method could also capture true structural behavior of the RCP, thus better reflecting the RCP reinforcing steel-cage design.

Performance of Thin-Wall Synthetic Fiber–Reinforced Concrete Pipes under Short and Long-Term Loading

Abstract Synthetic fibers have been recently used as a replacement for conventional steel reinforcement in concrete pipes to enhance their durability, ductility, shear strength, and flexural strength. However, there is very limited understanding of the long-term performance of thin-wall synthetic fiber–reinforced concrete pipes, as synthetic fiber has material properties that may change with a sustained load over time. This research investigates the performance of polypropylene fiber–reinforced concrete pipe under short and long-term loads in terms of strength, deflection response, strain response, crack width, and crack patterns. Concrete pipes with diameters of 1,200 and 1,500 mm with respective wall thicknesses of 50 and 63 mm were subjected to the short-term three-edge bearing test. To ensure maximum fiber contribution to pipe strength, a 9 kg/m3 fiber dosage was used with different amounts of steel reinforcement. For the long-term three-edge bearing test, a pipe with a diameter of 1,200 mm reinforced with fiber dosage of 9 kg/m3 along with steel reinforcement with an area of 5.7 cm2/m was tested for 30 days at 40 % of the ultimate load (Load Stage 1) obtained from the short-term test, for another 30 days at 50 % ultimate load (Load Stage 2), and subsequently at 70 % ultimate load for a final 30 days (Load Stage 3). Short-term results showed that synthetic fiber was a viable replacement for the steel reinforcement cage, as some of the tested pipe achieved the strength requirement specified by ASTM C76-15a, Standard Specification for Reinforced Concrete Culvert, Storm Drain, and Sewer Pipe. In response to sustained load, the tested pipe initially exhibited a linear response, followed by a stable response with a slight increase in deflection over time. Fiber creep did not significantly increase the crack width or affect the time dependence of the strain, indicating that the fibers adequately transfer the stress in the pipe wall and limit the crack width. The cracks propagated longitudinally at the invert, crown, and springline, where there were high flexural tensile stresses.

Predicting Hydrostatic Infiltration in Reinforced Concrete Sewer Pipes Considering Joint Gap and Joint Offset

AbstractGroundwater infiltration into underground sewer systems has long been a costly issue for municipalities. With reinforced concrete pipe (RCP) being a primary sewer system option, existing hy...

Indirect and Direct Design Methods for Design of Reinforced Concrete Pipe

There are currently two acceptable methods by which concrete pipe may be designed per the AASHTO Bridge Design Specifications: the direct design method and the indirect design method. The evaluation of applied load is similar for both methods, however, evaluation of the pipe’s capacity to resist applied load differs between the two methods. The indirect design method uses physical three edge bearing (TEB) testing at the production facility based on a relationship between the forces in the pipe wall in the installed condition compared with forces in the pipe wall from the TEB test. The direct design method follows the conventional design procedure for concrete members where demand versus capacity is determined using load and resistance factors to account for variability in applied loads and resistant capacity of the structure. Because of advances in computer technology, the direct method has become easier to apply than it was in the past. However, the indirect method, which has been used for approximately 70 years, has demonstrated conservatism and is a proven design method. Comparison of similar installations using the two methods has resulted in disagreements with respect to the minimum required reinforcement, however, both methods are adequately conservative, and each may have its place depending on the size and strength of the pipe. This paper presents the fundamental differences between the two design methods and offers some guidance on when to use each of them.

Modeling structural behavior of precast concrete pipe with single elliptical steel cage reinforcement

Using single elliptical (SE) cage reinforcement in reinforced concrete pipes (RCP) can reduce both the needed reinforcing steel and labor for manufacturing double and triple steel reinforcing cages. However, there is currently no robust tools to predict the structural behavior of RCP with SE reinforcement. In this study, non-linear 3D finite element model was developed to evaluate the load capacity of SE reinforced RCP. Model predictions were validated using experimental results on corresponding full-scale pipes. The model simulated load–deflection curves of RCP under the three-edge bearing test (TEBT) and predicted its load capacity with an average error of 9%. A parametric study was conducted to investigate the effects of SE cage rotation on the load capacity of RCP. It was found that rotation had minimal effect on the elastic behavior and stiffness of the pipe up to 1 mm vertical deflection. However, SE cage rotation had greater significance on the plastic response of the pipe when the steel reinforcement became fully engaged. The proposed model could provide a basis for developing design charts for RCP with SE reinforcement and quantify possible effects of SE reinforcing cage rotation on pipe load capacity.

Seismic fragility analysis of LNG sub-plant accounting for component dynamic interaction

Earthquakes can cause significant damage to liquefied gas terminals, a critical part of lifeline facilities of energy supply networks, failure of which may lead to loss of hazardous material, explosion, environmental contamination, loss of functionality and disruption of business. To date, seismic risk analysis of such facilities mainly focuses at component level, with the inherent dynamic interaction between the supporting structure and non-structural components not receiving the merited attention. In the present study, the seismic performance of an actual facility comprising of a piping system and a reinforced concrete (RC) supporting structure is analyzed through a finite element model in the nonlinear regime, both as coupled and decoupled case. Plastic strains are used as engineering demand parameters (EDP) to define leakage limit state for pipes. Since the RC pipe rack supporting structure is designed for low seismic loads, shear is recognized as the predominant failure mode. The same components are then analyzed in unison, considering coupling due to dynamic interaction. Fragility functions are estimated for both cases using multiple stripe analysis. A set of strong ground motions artificially generated using the specific barrier model, are employed for developing fragility curves. They are expressed with peak ground acceleration (PGA) as an intensity measure. Statistical estimation of the parameters of fragility functions are based on maximum likelihood method. It is inferred that in the decoupled case, pipes show higher vulnerability at lower PGA, at higher PGA pipe rack can fail suddenly resulting in total failure of the system. Moreover, in coupled case the fragility of the pipes and RC rack changes substantially because of the piping system boundary conditions. Thus, concluding that the risk estimation could be erroneous if dynamic interaction is neglected.

Investigation of structural behavior of precast concrete pipe with single elliptical steel cage reinforcement

Reinforced Concrete Pipe (RCP) with single elliptical (SE) reinforcement offers cost savings and is permitted by Canadian and American standards. Yet, its use has not yet gained momentum primarily due to limited knowledge of its structural performance. This study explores the structural behavior of full-scale 1050 mm and 1200 mm diameter RCP reinforced with SE cold drawn steel wire cage under the three-edge bearing test. Experimental results show that, given similar amount of reinforcing steel at the tension zone of the inner face of the invert and obvert of the pipe, RCP with SE reinforcing cage meets lower equivalent class than that of RCP with conventional double reinforcing cage. The absence of a second layer of reinforcement in the SE pipes produced more brittle failure characterized by radial tension, followed by concrete slabbing. Increasing the steel reinforcement ratio improved the 0.3-mm crack load and ultimate load capacity up to a certain threshold, beyond which adding more steel did not enhance the results. Results indicate that RCP with SE reinforcement designed per current standards did not meet the specified 0.3-mm crack and ultimate load capacity. Hence, pertinent provisions in CSA A257.2 and ASTM C76 for RCP need to be updated with specific and more suitable guidance for single elliptical cage RCP.

Quantifying Resistance of Reinforced Concrete Pipe Joints to Water Infiltration

AbstractHydrostatic joint performance for infiltration is a key design requirement for a reinforced concrete pipe (RCP) to withstand in situ groundwater pressure. However, current standards and tes...

Test-loading Capacity Estimation of Slip-lined RCPs using a plastic approach

As many reinforced concrete pipes (RCPs) need to be rehabilitated due to the reconstruction, expansion of highways and structural damage. Inserting a corrugated steel pipe (CSP) into the existing RCP is an economical rehabilitation technique in China, the current research seeks to better understand the performance of the RCP rehabilitated with grouted CSP by using the reinforced concrete pipes (RCPs) as the host pipes. Experiments were conducted to (1) determine the test-loading capacity of five specimens; (2) understand the role of the liner (CSP); (3) understand the influence of eccentric rehabilitation on the test-loading capacity of the slip-lined pipe; (4) explore an approach to estimate the load-carrying capacity of the rehabilitated pipes. The test-loading capacity of an RCP rehabilitated with grouted CSP mainly depends on the RCP and the grout before the first peak value of the applied versus diameter change curve, CSP improved the maximum test-loading capacity and ductility of rehabilitated pipe. The test-loading capacity of an eccentric rehabilitated pipe was lower than that of a concentric rehabilitated pipe. The comparison of the calculated results showed that the plastic approach was reasonable for an RCP rehabilitated grout CSP. Meanwhile, an approach for analyzing a vertical eccentric rehabilitated pipe was proposed based on the plastic approach. The errors between the theoretical results and experimental results were basically less than 30%.

Influence of Grout Strength and Residual Deformation on Performance of Rehabilitated RC Pipes

AbstractInserting a corrugated steel pipe (CSP) into an existing reinforced concrete pipe (RCP) is a common culvert rehabilitation technique in China. However, few studies have focused on the influ...

A Failure Risk-Based Culvert Renewal Prioritization Framework

Transportation agencies are currently challenged to keep up with culvert infrastructure that is rapidly deteriorating due to lack of adequate maintenance and capital improvement. It is imperative for the transportation agencies to identify and rehabilitate deteriorated culverts prior to their failures. Among several concerns, lack of rational rehabilitation prioritization tools is foremost. Complicating this need further, current practices vary widely across the state departments of transportation (DOTs) which makes it difficult to develop a universal approach for prioritizing failing culverts. This paper presents and demonstrates a failure risk-based culvert prioritization approach that is compliant with the inspection procedures of the South Carolina DOT. The approach presented in this paper is specifically developed for reinforced concrete pipe (RCP) and corrugated metal pipe (CMP) materials because of their wide popularity. Outcomes from a survey of state DOTs informed the development of parametric weightings using the principles of analytical hierarchy process (AHP). Weightings developed for several critical inspection parameters are combined with the corresponding condition assessment scores to determine the failure criticality of culverts, which are subsequently combined with estimated failure consequences to determine failure risk estimates. The prioritization approach is demonstrated using the condition assessment scores of over 5200 culvert structures in South Carolina.

Evaluation of Synthetic Fiber Reinforced Concrete Pipe Performance Using Three-Edge Bearing Test

Abstract Synthetic fibers have recently been used in a concrete mix in an attempt to produce a new concrete pipe system that is cheaper, lighter, and more flexible than conventional steel reinforced concrete pipes. However, no structural design codes have been introduced for synthetic fiber reinforced concrete pipes evaluation. There is little in the literature regarding synthetic fiber applications in concrete pipes. This study focuses on the evaluation of the synthetic fiber reinforced concrete pipes in terms of ASTM requirements for strength, stiffness, and ductility. The performance of the synthetic fiber reinforced concrete pipes was evaluated using a three-edge bearing test in accordance with ASTM protocols and using three pipe diameters: 600, 1,200, and 1,500 mm. Fiber dosages ranged from 4.75 to 18 kg/m3, and different areas of one steel cage layer were used to reinforce the concrete pipes. The results show that using synthetic fiber increased the cracking load (produces 0.3-mm crack width), ultimate load, stiffness, and ductility of tested pipes. Also, using synthetic fiber lowered the production cost, as the reduction in the steel cage area ranged from 51 to 100 %.

Experimental Investigation of Thin-wall Synthetic Fiber Reinforced Concrete Pipes

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Probabilistic Lifetime Assessment of RC Pipe Piles Subjected to Chloride Environments

AbstractThis paper presents a probabilistic approach for evaluating the lifetime of reinforced concrete (RC) pipe piles subjected to chloride environments. A predictive model is developed for model...

Critical Analysis of International Precast Concrete Pipe Standards

Reinforced concrete pipe (RCP) standard guidelines and industry practice have rather been disconnected from the end-users’ expectations. No genuine effort has so far been made to create synergy between the expertise gained and advances made around the world. With the advent of strong competition from flexible pipe products and changing end-user expectations, a critical look at the current state-of-the-art is needed. In the present paper, RCP standards from a study area representing a quarter of the world’s population (Canada, United States, United Kingdom, China, Australia and New Zealand) were critically analyzed. Comparisons were made in terms of product and material requirements, structural load testing, hydrostatic performance, and durability requirements. It is shown that the RCP sector lags modern developments in concrete technology, standard code advances and materials innovations. The analysis also revealed various knowledge gaps in terms of the mechanical, hydrostatic and durability performance of RCP. Recommendations emanating from this critical analysis aim at tailoring performance-based guidelines that can better capture current market needs and user expectations.

<b>A comparative experimental investigation of reinforced-concrete pipes under three-edge-bearing test: Spigot and Pocket and Ogee Joint pipes

An experiment on the behavior of two types of circular reinforced concrete pipes under three-edge-bearing test is analyzed and discussed. Current study compares the strength of spigot-pocket (SPP) and ogee joint pipes (OJP). In the experimental analyses thirty-two pipes, nominal diameter 800 and 1200 mm, divided into two series of 16 pipes each, were tested. Each series was composed of 12 spigot-pocket pipes (SPP) and 4 ogee joint pipes (OJP). Experimental results of the loading versus displacement curves indicated that pipes behave similarly to a circular ring, since the OJP presented maximum loads 12 and 4% higher than those obtained for SPP respectively for nominal diameters 800 and 1200 mm. Pocket influenced load cracking, with 6.4 and 33% higher for SPP when compared to OJP for nominal diameters 800 and 1200 mm, respectively. Further, the presence of the pocket increased the pipe´s stiffness.

Numerical Analyses for Centrifugal Reinforced Concrete Pipe Loaded by Internal Loading Method

Numerical Analyses for Centrifugal Reinforced Concrete Pipe Loaded by Internal Loading Method

Application of Non-pressure Reinforced Concrete Pipes in Modern Construction and Reconstruction of Highways

Modern highway construction technologies provide for the quality water discharge systems to increase facilities’ service life. Pipeline operating conditions require the use of durable and reliable materials and structures. The experience in using reinforced concrete pipes for these purposes shows their utilization efficiency. The present paper considers the experience in the use of non-pressure reinforced concrete pipes manufactured by the German company SCHLOSSER-PFEIFFER under the Ural region geological and climatic conditions. The authors analyzed the actual operation of underground pipelines and effective loads upon them. A detailed study of the mechanical properties of reinforced concrete pipes is necessary to improve their production technology and to enhance their serviceability. The use of software-based methods helped to develop a mathematical model and to estimate the strength and crack resistance of reinforced concrete pipes at different laying depths. The authors carried out their complex research of the strain-stress behaviour of reinforced concrete pipes and identified the most hazardous sections in the structure. The calculations performed were confirmed by the results of laboratory tests completed in the construction materials, goods, and structures test center. Based on the completed research, the authors formulated their recommendations to improve the design and technology of non-pressure reinforced concrete pipes.